/Engine/Source/Runtime/Engine/Classes/Engine/GameInstance.h
Call to create the game mode for a given map URL
virtual [AGameModeBase](API\Runtime\Engine\GameFramework\AGameModeBase) * CreateGameModeForURL ( [FURL](API\Runtime\Engine\Engine\FURL) InURL, [UWorld](API\Runtime\Engine\Engine\UWorld) * InWorld )